This invention relates to a sealing system.
This invention has particular but not exclusive, application to sealing systems for chambers adapted to be evacuated. This invention is herein illustrated in the context of a sealing system for an evacuatable airlock which acts as an antechamber for a vapour deposition chamber. However, it will be understood that the invention is not limited to this particular environment.
Many different sealing systems exist for enabling evacuation of air from vacuum chambers whilst closed, yet enable items to be introduced to or removed from the vacuum chamber whilst open.
Disadvantages with known sealing systems range from high cost and poor reliability to large size where limited space is available.
This invention in one aspect resides in a method of sealing a port having a sealing face with a gate having a complementary sealing face, the method including:
abutting the gate""s sealing face with the port""s sealing face and translating the gate""s sealing face relative to the port""s sealing face in a direction parallel to the port""s sealing face.
In the preferred embodiment the abutment of the sealing faces and the translation of the gate""s sealing face relative to the port""s sealing face occur simultaneously, although they could be sequential movements.
In the preferred embodiment the gate""s sealing face approaches the port""s sealing face during closing in a direction which includes orthogonal and parallel components relative to the plane of the port""s sealing face.
The gate""s sealing face or port""s sealing face will normally include a resilient member and the resilient member will slide or distort during the relative translation of the sealing faces. In the preferred embodiment, the resilient member is an O-ring which forms part of the sealing face of the gate.
In a second aspect the invention resides in a sealing system including:
gate having a sealing face; and
a port having a complementary sealing face, wherein, upon closing, the respective sealing faces abut and the gate""s sealing face translates relative to the port""s sealing face in a direction parallel to the abutting sealing faces.
Preferably, one of the sealing faces includes a resilient member and preferably the resilient member is an O-ring. The relative translation between the abutting sealing faces causes sliding or distortion of the O-ring which facilitates improved sealing.
Preferably, the gate is pivotably mounted via a mobile pivot axis to a crank member which, in turn, is pivotably mounted about a fixed pivot axis, the mobile pivot axis and fixed pivot axis being substantially parallel.
Preferably, the fixed pivot axis is parallel to and spaced from the plane of the sealing face of the port.
Preferably, during closing, the mobile pivot axis moves in a direction which includes orthogonal and parallel components relative to the plane of the port""s sealing face.
Preferably, the crank member is pivoted in a first rotational direction about the fixed pivot axis during closure and the gate member is biased relative to the crank member in the first rotational direction.
In another aspect the invention resides in a gate adapted to be rotated in a first direction to sealably cover an aperture, the gate being pivotably mounted to a crank which is pivotably mounted about a fixed axis.
Preferably, a biasing member is disposed intermediate the crank and gate for biasing the gate in the first direction relative to the crank.